1. Field of the Invention
This invention generally relates to electrical connection terminals and, more particularly, to connection terminals for baseless cartridge type light bulbs having rigid-wire loop contacts extending from the bulb ends.
2. Description of the Related Art
Baseless cartridge type bulbs are standard items typically used in automotive applications such as overhead and interior lamps. Cartridge bulbs are formed from cylindrically shaped glass envelopes which contain longitudinal filaments. During manufacture, each cylinder end is pinched over a small rigid-wire loop forming an external contact for one end of the internal filament.
Conventional terminals for cartridge type bulbs are generally formed of resilient conducting material and typically hold the bulb wire loops either in tension or compression to maintain electrical contact. Because the supporting structure for the wire loop ends of a cartridge bulb is formed of glass, the axial length of a bulb between its wire loops can have a relatively large tolerance. For example, a bulb having an approximate length of 1.7 inches, typically varies by 0.050 inches in length. Due to this relatively large tolerance on bulb length, conventional terminals generally subject cartridge bulbs to relatively large tension or compression forces in order to reduce the possibility of intermittent electrical contact. This pressure, if excessive, can damage the glass envelopes of the bulbs.
Another problem commonly associated with prior art cartridge bulb terminals concerns the difficulty in inserting or removing a bulb from the terminal pairs within the lamp housing or socket assembly (hereinafter generally termed "housing"). For ease of manufacture, it is also desirable to have a terminal design which allows for easy economical installation into the housing containing the bulb.